For the purpose of efficient containerized freight transportation, a freight support means called a rack is often used. The rack generally has a shelf-like portion (freight mounting frame) allowing freight to be housed one above another, along with a base member placed on the floor plate of a container. The shelf-like portion is used for housing as much freight as possible inside the container for efficient transportation. Such a rack is described, for example, in the following Patent Literature 1.
The freight rack described in Patent Literature 1 is shown in FIGS. 16 and 17, and has the following characteristics.
i) As in FIGS. 16A and 16B, a freight mounting frame 20 is supported by four pillars 31 and 41 standing on the right and left sides of a base member 10 with an interval in a front and rear direction. As the height of each supporting point of the freight mounting frame 20 by those pillars 31 and 41 is changeable, freight (such as automobiles) in different sizes may be appropriately housed in a container.
ii) The four pillars 31 and 41 as well as the freight mounting frame 20 may be folded on the base member 10 as in FIGS. 16C and 16D for a returning purpose, for example, after the completion of freight transportation. That is, each of the pillars 31 and 41 and the freight mounting frame 20 are coupled together with changeable angles in a vertical, longitudinal plane. Each of the pillars 31 and 41 stands on the base member 10 so as to be laid down forward or rearward. When the freight mounting frame 20 is set horizontally as in the figure C, the four pillars 31 and 41 may be laid down altogether, and the freight mounting frame 20 may be stacked on the base member 10 as in the figure D.
iii) Each of the pillars 31 and 41 and the freight mounting frame 20 are coupled to each other with a structure shown in FIGS. 17A and 17B. Specifically, each pillar 31 and 41 has a groove shape with a C-shaped cross section. The freight mounting frame 20 has a moving body part 20Y that is rotatable through a shaft portion 20X extending right and left, and each moving body part 20Y is housed inside the groove space of each pillar 31 and 41. At contacting sections between the moving body parts 20Y and the pillars 31 and 41, a roller or a low frictional material is mounted so as to make the vertical movement of the moving bodies smooth. It is noted that reference numeral 20Z in the figures indicates a support pin that is inserted through holes of the pillars 31 and 41 so as to stop the vertical movement of the moving bodies 20Y.